JLB
June 12th, 2007, 7:44:29 AM
http://www.nytimes.com/2007/06/12/science/12obse1.html?ref=science
Carbon dioxide and other greenhouse gases get most of the blame for climate change. And rightly so, as they are by far the most dominant influence globally.
But don’t forget dirt.
Building on research from earlier in the decade, scientists at the University of California, Irvine, have calculated the warming effect of soot falling on Arctic snow. And the result may come as a surprise: in the Arctic, dirty snow may be responsible for more warming than greenhouse gases.
“It turns out that nothing is more efficient at increasing the Earth’s temperature than soot in snow,” said Charles S. Zender, a professor of Earth system science at the university.
Soot, from coal burning, inefficient cookstoves and forest and agricultural fires, falls in the Arctic, darkening snow. Dark colors absorb more sunlight than lighter colors and radiate more heat in return.
Carbon dioxide and other greenhouse gases get most of the blame for climate change. And rightly so, as they are by far the most dominant influence globally.
But don’t forget dirt.
Building on research from earlier in the decade, scientists at the University of California, Irvine, have calculated the warming effect of soot falling on Arctic snow. And the result may come as a surprise: in the Arctic, dirty snow may be responsible for more warming than greenhouse gases.
“It turns out that nothing is more efficient at increasing the Earth’s temperature than soot in snow,” said Charles S. Zender, a professor of Earth system science at the university.
Soot, from coal burning, inefficient cookstoves and forest and agricultural fires, falls in the Arctic, darkening snow. Dark colors absorb more sunlight than lighter colors and radiate more heat in return.